How to handle keyboard controls in Arkanoid game

Question

I'm making simple Arkanoid clone in Unity with both keyboard and mouse controls available. When I gave it to my colleagues to test one complain was that keyboard controls are not precise enough,. The problem is that I don't really know how to find a balance between two factors:

• If I make paddle speed too high then it lacks precision to position it just right to make ball go to the last few blocks.
• If I make paddle speed too slow then it's going to be difficult to reach ball in time.

I thought about it and I don't recall any version of arkanoid that solved that problem. Currently I have 3 ideas:

1. Make two (or more) keys to go in each direction. One will go faster and another slower.
2. Instead of making multiple buttons lets allow player to change speed of paddle during the game. Probably by entering number from 0-9 on keyboard.
3. Just leave it like it is now. Other control schemes are not intuitive enough.

Does anyone have any experience with this? Which approach is the most reasonable?

Edit: Code I'm using:

    Vector3 pz = transform.position;
    pz.y = y;
    pz.z = 0;
    if (Input.GetKey(KeyCode.LeftArrow)) {
        pz.x -= Time.deltaTime * KEYBOARD_SPEED_MULTIP;
    }
    if (Input.GetKey(KeyCode.RightArrow)) {
        pz.x += Time.deltaTime * KEYBOARD_SPEED_MULTIP;
    }
    pz.x = Mathf.Clamp(pz.x, -60, 60);
    rb.MovePosition(pz);

I simply move paddle by constant speed which includes timedelta. And then I clamp position to screen.

Answer 1

Since 2 people commented right answer, but none of them has posted response I'm going to respond to my own question.

Adding acceleration seems to be right option. Controls are still not that good as mouse, but I don't think that it can be made significantly better without mouse or touch screen.

I changed rigidbody type to dynamic and removed multiplier constant because I used mass instead. I also added additional code to clamp position and assure that paddle only has inertia when player is holding button.

Result code looks like this:

    if (Input.GetKey(KeyCode.LeftArrow)) {
        if (direction > 0) {
            rb.velocity = Vector2.zero;
        }
        rb.AddForce(new Vector2(-Time.deltaTime, 0), ForceMode2D.Force);
        direction = -1;
    }
    else if (Input.GetKey(KeyCode.RightArrow)) {
        if (direction < 0) {
            rb.velocity = Vector2.zero;
        }
        rb.AddForce(new Vector2(Time.deltaTime, 0), ForceMode2D.Force);
        direction = 1;
    }
    else
    {
        rb.velocity = Vector2.zero;
        direction = 0;
    }
    Vector3 pz = transform.position;
    if (Mathf.Abs(pz.x) > 60) {
        pz.x = Mathf.Clamp(pz.x, -60, 60);
        rb.MovePosition(pz);
    }